Entrainment and scattering in microswimmer-colloid interactions
We use boundary element simulations to study the interaction of model microswimmers with a neutrally buoyant spherical particle. The ratio of the size of the particle to that of the swimmer is varied from R\supP / R\supS \ll 1, corresponding to swimmer--tracer scattering, to R\supP / R\supS \gg 1, a...
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| Format: | Journal article |
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American Physical Society
2017
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| _version_ | 1826273756417359872 |
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| author | Shum, H Yeomans, J |
| author_facet | Shum, H Yeomans, J |
| author_sort | Shum, H |
| collection | OXFORD |
| description | We use boundary element simulations to study the interaction of model microswimmers with a neutrally buoyant spherical particle. The ratio of the size of the particle to that of the swimmer is varied from R\supP / R\supS \ll 1, corresponding to swimmer--tracer scattering, to R\supP / R\supS \gg 1, approximately equivalent to the swimmer interacting with a fixed, flat surface. We find that details of the swimmer and particle trajectories vary for different swimmers. However, the overall characteristics of the scattering event fall into two regimes, depending on the relative magnitudes of the impact parameter, \rho, and the collision radius, R^coll=R\supP + R\supS. The range of particle motion, defined as the maximum distance between two points on the trajectory, has only a weak dependence on the impact parameter when \rho R^coll the range decreases as a power law in \rho and is insensitive to the size of the particle. We also demonstrate that large particles can cause swimmers to be deflected through large angles. In some instances, this swimmer deflection can lead to larger net displacements of the particle. Based on these results, we estimate the effective diffusivity of a particle in a dilute bath of swimmers and show that there is a non-monotonic dependence on particle radius. Similarly, we show that the effective diffusivity of a swimmer scattering in a suspension of particles varies non-monotonically with particle radius. |
| first_indexed | 2024-03-06T22:33:03Z |
| format | Journal article |
| id | oxford-uuid:58e8a89c-73dc-40cd-802e-eb2d54d24cb0 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T22:33:03Z |
| publishDate | 2017 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | oxford-uuid:58e8a89c-73dc-40cd-802e-eb2d54d24cb02022-03-26T17:06:37ZEntrainment and scattering in microswimmer-colloid interactionsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:58e8a89c-73dc-40cd-802e-eb2d54d24cb0Symplectic Elements at OxfordAmerican Physical Society2017Shum, HYeomans, JWe use boundary element simulations to study the interaction of model microswimmers with a neutrally buoyant spherical particle. The ratio of the size of the particle to that of the swimmer is varied from R\supP / R\supS \ll 1, corresponding to swimmer--tracer scattering, to R\supP / R\supS \gg 1, approximately equivalent to the swimmer interacting with a fixed, flat surface. We find that details of the swimmer and particle trajectories vary for different swimmers. However, the overall characteristics of the scattering event fall into two regimes, depending on the relative magnitudes of the impact parameter, \rho, and the collision radius, R^coll=R\supP + R\supS. The range of particle motion, defined as the maximum distance between two points on the trajectory, has only a weak dependence on the impact parameter when \rho R^coll the range decreases as a power law in \rho and is insensitive to the size of the particle. We also demonstrate that large particles can cause swimmers to be deflected through large angles. In some instances, this swimmer deflection can lead to larger net displacements of the particle. Based on these results, we estimate the effective diffusivity of a particle in a dilute bath of swimmers and show that there is a non-monotonic dependence on particle radius. Similarly, we show that the effective diffusivity of a swimmer scattering in a suspension of particles varies non-monotonically with particle radius. |
| spellingShingle | Shum, H Yeomans, J Entrainment and scattering in microswimmer-colloid interactions |
| title | Entrainment and scattering in microswimmer-colloid interactions |
| title_full | Entrainment and scattering in microswimmer-colloid interactions |
| title_fullStr | Entrainment and scattering in microswimmer-colloid interactions |
| title_full_unstemmed | Entrainment and scattering in microswimmer-colloid interactions |
| title_short | Entrainment and scattering in microswimmer-colloid interactions |
| title_sort | entrainment and scattering in microswimmer colloid interactions |
| work_keys_str_mv | AT shumh entrainmentandscatteringinmicroswimmercolloidinteractions AT yeomansj entrainmentandscatteringinmicroswimmercolloidinteractions |